.\"	$NetBSD: ulimit.3,v 1.9 2010/04/30 05:09:23 jruoho Exp $
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.\" by Klaus Klein.
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.Dd April 30, 2010
.Dt ULIMIT 3
.Os
.Sh NAME
.Nm ulimit
.Nd get and set process limits
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In ulimit.h
.Ft long int
.Fn ulimit "int cmd" ...
.Sh DESCRIPTION
The
.Fn ulimit
function provides a method to query or alter resource limits of the calling
process.
The method to be performed is specified by the
.Fa cmd
argument; possible values are:
.Bl -tag -width UL_GETFSIZEXX
.It Li UL_GETFSIZE
Return the soft file size limit of the process.
The value returned is in units of 512-byte blocks.
If the result cannot be represented in an object of type
.Fa long int ,
the result is unspecified.
.It Li UL_SETFSIZE
Set the hard and soft file size limits of the process to the value of the
second argument passed, which is in units of 512-byte blocks, and which is
expected to be of type
.Fa long int .
The new file size limit of the process is returned.
Any process may decrease the limit, but raising it is only permitted if
the caller is the super-user.
.El
.Pp
If successful, the
.Fn ulimit
function will not change the setting of
.Va errno .
.Sh RETURN VALUES
If successful, the
.Fn ulimit
function returns the value of the requested limit.
Otherwise, it returns \-1, sets
.Va errno
to indicate an error, and the limit is not changed.
Therefore, to detect an error condition applications should set
.Va errno
to 0, call
.Fn ulimit ,
and check if \-1 is returned and
.Va errno
is non-zero.
.Sh ERRORS
The
.Fn ulimit
function will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Fa cmd
argument is not valid.
.It Bq Er EPERM
It was attempted to increase a limit, and the caller is not the super-user.
.El
.Sh SEE ALSO
.Xr getrlimit 2 ,
.Xr setrlimit 2
.Sh STANDARDS
The
.Fn ulimit
function conforms to
.St -xsh5
and
.St -p1003.1-2001 .
It was marked as obsolete in the
.St -p1003.1-2008
revision, which recommended the use of
.Xr getrlimit 2
and
.Xr setrlimit 2
instead, noting that because
.Fn ulimit
uses the type
.Vt long
rather than
.Vt rlim_t ,
it may not be sufficient for file sizes on many current systems.
